21111113011 has 4 divisors (see below), whose sum is σ = 21509435952. Its totient is φ = 20712790072.

The previous prime is 21111113003. The next prime is 21111113137. The reversal of 21111113011 is 11031111112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21111113011 - 2³ = 21111113003 is a prime.

It is a super-2 number, since 2×21111113011² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21111112982 and 21111113000.

It is not an unprimeable number, because it can be changed into a prime (21111113311) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 199161391 + ... + 199161496.

It is an arithmetic number, because the mean of its divisors is an integer number (5377358988).

Almost surely, 2^21111113011 is an apocalyptic number.

21111113011 is a deficient number, since it is larger than the sum of its proper divisors (398322941).

21111113011 is an equidigital number, since it uses as much as digits as its factorization.

21111113011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 398322940.

The product of its (nonzero) digits is 6, while the sum is 13.

Adding to 21111113011 its reverse (11031111112), we get a palindrome (32142224123).

The spelling of 21111113011 in words is "twenty-one billion, one hundred eleven million, one hundred thirteen thousand, eleven".